10 Mar 2017
Every parent knows that children love lollies, cookies and sweet drinks. But don’t be too hard on them; it’s all a delicious ploy by evolutionary biology to ensure survival of the youngest members of our species. Research shows kids are hardwired to have a stronger sugar preference than adults, and newborns will show a strong preference for sugar-sweetened solutions.
A child’s sensory world is very different from ours. They will salivate over treats far too salty or sweet for you and me, and are generally more sensitive to bitter flavours. One reason is simply that children need more sugar to support their rapid growth and development. A strong preference for sweet foods, which in nature were not always as ubiquitous as they are now, may have conferred a survival advantage.
Avoiding bitter foods makes sense too. In nature the bitter flavour often represents secondary plant compounds such as alkaloids and terpenes, which may be poisonous. By avoiding the flavour that may go with dangerous phytochemicals, again, children may have been using their taste buds to survive.
Sugar not only tastes extra good to little ones, it makes them feel extra good too. Doctors know this and so will use sugar-sweetened liquid as a natural pain reliever in infants too young for traditional analgesics.
There is good news though — at the age at which children stop growing, their preference for sugar shrinks as well. By age 15 or 16, most teenagers show about the same preference as adults for sweet foods and drinks. The age at which that preference changes can be predicted by measuring bone turnover — when bone stops growing, kids may stop raiding the lolly jar as well. One reason for this is that growing bones secrete hormones such as insulin and leptin that may stimulate the brain and and influence metabolism, taste and cravings.